Linear Systems

The linear systems module has also been moved into the kernel. Linear systems can now be created on both affine and projective spaces rather than just projective. The following changes were made.

• The comparison maps between CoefficientMap(L) and PolynomialMap(L) for a linear system L are now returned as maps which take an argument xrather than these intrinsics taking x as a second argument.
• The various intrinsics Subsystem(L,X) where L is a linear system and X is some other data have been renamed LinearSystem(L,X).